The present invention relates to snowmobile suspensions and more particularly relates to front ski suspensions for snowmobiles.
The most common type of suspension used heretofore for snowmobile skis has included a leaf spring extending lengthwise of and having an end fixed to a ski with the spring additionally being fastened at a location intermediate of its ends to a steering spindle. These suspensions further include a shock absorber having one end secured to the ski at a location adjacent one end of the spring and having its other end secured either to the spindle or to the spring in the vicinity of the spindle whereby the shock absorber operates to damp the action of the spring. This type of suspension has the disadvantage that there is not a one-to-one correspondence between the deflection of the spring and the action of the shock absorber and consequently the skis are not as much under control as is necessary for contributing to a smooth ride.
During the past ten years, various designs of snowmobile ski suspensions have been proposed wherein a shock absorber is mounted in axial alignment with a coil compression spring between the snowmobile frame and the ski so that a one-to-one correspondence between spring and shock absorber action occurs. Such designs are disclosed in U.S. Pat. No. 3,674,104 granted to Gostomiski on July 4, 1972, U.S. Pat. No. 3,692,130 granted to Stacey on Sept. 19, 1972, U.S. Pat. No. 3,931,862 granted to Cote on Jan. 13, 1976 and U.S. Pat. No. 3,977,485 granted to West et al. on Aug. 31, 1976. Each of these patented designs suffers from one or more of the disadvantages due to their suspension struts lacking lengthwise compactness, of having a relatively short travel or of being structured such as to not easily accommodate different sizes of coil compression springs or such that the pre-set compression of their springs cannot be adjusted without at least partial disassembly of the struts.